1. Field of the Invention
The present invention relates to an image display apparatus and, more particularly, to an image display apparatus for displaying an image larger than a display screen by panning.
2. Description of the Prior Art
There are several techniques for displaying an image larger than a display screen. In one conventional technique, an image is reduced and the reduced image is displayed over the entire screen. The overall image can easily be visually recognized, but minute details thereof cannot be precisely checked. In another conventional technique, a viewing position is shifted among displayed image portions each of which is smaller than the entire image, thereby enabling grasp of the entire image. This technique is called panning. Panning is an effective technique to check the details of an image. However, with a conventional operation using only a keyboard, an operator is overloaded when he checks the image with natural operation feeling. When only a pointing device is used, the display screen is often shifted, and the viewing position of the operator cannot be stabilized, resulting in inconvenience.